Just start a conversation with him as if he was anyone normal. So, you know he likes a Landy and some meat, why not ask about that sort of thing?

Nothing wrong with recognising and talking to "slebs", as long as you're not stalkerish! Have ended up having many an interesting conversation with well known folks around my part of London. Make the most of it!

Another thought - Why not give him your laptop and let him do a live chat with the good people of STW right here and now!